a A peak traveler is estimated to travel from 6:00 a.m. to 9:00 a.m. and 4:00 p.m. to 7:00 p.m.

Key:
Very large = over 3 million population (e.g., New York-Northern New Jersey).
Large = 1 million-3 million population (e.g., San Diego).
Medium
= selected areas with 500,000-1 million population (e.g., Charlotte).
Small = selected areas under 500,000 population (e.g., Colorado Springs).